Drive reading or writing DVDs.

Motherboard connector for M.2 devices.

Motor rotating HDD platters.

Hardware managing storage-device communication.

Drive reading or writing Blu-ray discs.

Physical keying arrangement identifying an M.2 interface.

PCB controlling hard-drive electronics.

PCB providing storage-device connections.

Drive reading or writing floppy disks.

M.2 key commonly used for PCIe/NVMe storage.